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Information

Editors

MartinaBachmann
KristiinaHersio
PerttiPere

Preoperative Assessment

Essentials

  • The aim of preoperative assessment is to weigh, how decisively the operation is expected to improve the patient's quality of life considering the risks associated with the operation.
  • The physician referring the patient for surgery should also assess and improve the patient's eligibility for anaesthesia and operation.
  • The task of the referring physician is to
    • individually assess the appropriateness and the expected benefit of the proposed surgery
    • carry out the set preoperative investigations
    • inform the surgeon about the patient's comorbidities and operative risks which might affect the outcome of surgery
    • assess the patient's physical functional capacity and to optimize nutrition
    • treat chronic diseases so that they are in optimal control and that control is maintained
    • provide factual information to the patient concerning the operation and the hospital care and to dispel unnecessary fears
    • assess the need for postoperative rehabilitation and to arrange for the rehabilitative measures in the primary care
    • explore the patient's social and living conditions in order to assess whether he/she is suitable for day or short stay surgery procedure.
  • As the share of day and short stay surgery increases, even more emphasis is put on the cooperation between the referring general practitioner and the specialized care.

Assessment of operative risk

  • The aim of anaesthesiological assessment is to identify the risks associated with anaesthesia and with the planned intervention and to reduce these risks.
  • The risks derive from three factors: the physical and mental condition of the patient, the surgical disease and its management, and the anaesthesia required.
  • The anaesthesia risk assessment using the ASA-classification (ASA = American Society of Anesthesiologists Physical Status; scale I-V http://www.asahq.org/resources/clinical-information/asa-physical-status-classification-system; here adapted) is based on the general clinical condition of the patient.
    • ASA I: A normal healthy patient, non-smoking, minimal alcohol use
    • ASA II: A patient with mild systemic disease without substantive functional limitations. E.g. smoking, moderate consumption of alcohol, pregnancy, significant obesity (BMI 30-40), well-controlled hypertension or diabetes.
    • ASA III: A patient with severe systemic disease. Substantive functional limitations. One or more moderate to severe diseases, alcohol dependence, implanted pacemaker, dialysis treatment, a history of myocardial infarction, cerebral infarction, cerebral haemorrhage or TIA > 3 months earlier, coronary stenting > 3 months earlier or stable angina, morbid obesity (BMI > 40).
    • ASA IV: A patient with a systemic disease that is a constant threat to life. Acute myocardial ischaemia, severe valvular dysfunction, coronary stenting < 3 months earlier.
    • ASA V: A moribund patient who is not expected to survive without the operation.
  • Operative mortality rate is about 0.2% for healthy patients in ASA class I and 50% for patients in ASA class V.

Preparation for surgery Preoperative Fasting for Adults to Prevent Perioperative Complications, Early Versus Delayed (Traditional) Oral Fluids and Food for Reducing Complications after Major Abdominal Gynaecologic Surgery, Peri-Operative Glycaemic Control Regimens for Preventing Surgical Site Infections in Adults, Preoperative Physical Therapy for Elective Cardiac Surgery Patients

  • The surgical team and the general practitioner should agree on the basic investigations that can be carried out in primary care. The aim is to minimise the postponement of the operation and shorten the number of preoperative inpatient days. The investigations should be performed in good time so as to allow sufficient time frame for the initiation of treatment called for by the possible findings. The patient's primary diseases should be in as good control as possible and the patient's nutrition should be optimized.
  • Before suggesting surgery to the patient, the treating physician should preliminarily consider the availability of the particular surgery, the hazards associated with the intervention and the arrangement of rehabilitation during recovery.
  • While the patient is on the waiting list, the treating physician must monitor for changes in the patient's health and performance status that could increase the operative risk.
    • TIA or stroke
    • unstable angina pectoris, myocardial infarction or exacerbation of heart failure
    • uncontrolled diabetes or emergence of complications
    • worsening of COPD.
  • Acute respiratory tract infection is an indication to postpone elective surgery performed under general anaesthesia.

Preoperative laboratory investigations

  • Preoperative screening tests (ECG, chest x-ray, determination of haemoglobin, electrolyte and creatinine concentrations) do not provide any benefit in the preoperative assessment of well-controlled patients.
  • The majority of the basic investigations can be carried out on an outpatient basis.
  • An otherwise healthy patient aged less than 50 years (ASA I)
    • No routine investigations (except Hb for menstruating women)
  • An otherwise healthy patient over 50 (ASA I)
    • Basic blood count with platelet count; ECG for men
  • Different investigations and their indications in surgical patients
    • ECG
      • Men over 50 years, women over 65 years of age
      • Hypertension
      • Other significant cardiovascular disease
      • Diabetes
      • Intervention in the thoracic region
    • Chest x-ray
      • Chronic cardiac or pulmonary diseases that reduces functional capacity
    • Electrolytes, creatinine
      • Hypertension
      • Diabetes and significant metabolic syndrome
      • Endocrinological diseases
      • Cytotoxic chemotherapy
      • Renal diseases
    • Coagulation studies (INR, platelet count)
      • Excessive consumption of alcohol
      • Anticoagulation therapy
      • Liver disease
    • Complete blood picture
      • Haematological diseases
      • Cytotoxic chemotherapy

Division of tasks between primary and specialist care

  • The referring general practitioner should inform the surgical team about:
    • the extent of the harm caused by the surgical disease to the patient
    • the estimated co-operating capacity of the patient during the recovery period
    • possible dementia and other factors affecting the decision to operate that may be missed in hospital investigations
    • other co-existing serious conditions, recent changes in the health status in particular, as well as the latest laboratory findings
    • social circumstances and the availability of an accompanying person for patients undergoing day surgery.
  • A specialist in internal medicine should prescribe the pre- and postoperative medication for patients with serious diseases.
  • An anaesthetist will assess the risks associated with the operation and is responsible for the perioperative medication. He/she also assesses the patient's eligibility for day surgery.
  • The operating surgeon makes the final decision on whether to operate. To support the decision making, comprehensive information concerning the patient's history must be at his/her disposal, as well as the viewpoints of all the consulting specialists on other fields (e.g. the anaesthetist).

The risks of co-existing common diseases on surgery

Coronary heart disease Alpha-2 Adrenergic Agonists for the Prevention of Cardiac Complications Among Patients Undergoing Cardiac Surgery, Perioperative Betablockers for Preventing Surgeryrelated Mortality and Morbidity in Adults Undergoing Cardiac Surgery, Alpha-2 Adrenergic Agonists for the Prevention of Cardiac Complications Among Patients Undergoing Non-Cardiac Surgery

  • The most important single disease as regards operative risk. Preliminary estimation of exercise tolerance can be judged from the medical history. The risk of cardiac complications is low if the patient is able to briskly perform everyday tasks at home and e.g. to climb one flight of stairs, carrying a small shopping bag, without cardiac symptoms.
  • Operative risk is increased significantly, and the patient should be operated on in life-threatening situations only, if
    • less than 6 weeks have passed since myocardial infarction, balloon angioplasty, coronary stenting or coronary artery by-pass graft
      • A non-acute operation should not be carried out earlier than 6 months after the insertion of a drug-eluting stent; in a patient with a stent, antithrombotic medication should not be interrupted.
    • the patient has poor exercise tolerance or heart failure after myocardial infarction.
  • If the patient has severe or unstable angina pectoris, it is recommendable to treat its cause first before intermediate or major surgery.
  • Operative risk is increased slightly if
    • 3 months have passed since myocardial infarction, and the patient has good exercise tolerance. Diabetes increases the risk.
    • the patient has stable angina pectoris with good exercise tolerance.
  • Initiation of a beta blocker and a statin is considered for patients with coronary heart disease undergoing vascular surgery. If the patient already uses a beta blocker, it should be continued until the operation, but the initiation of new medication must be made with consideration according to the recommendation by a cardiologist.
  • A small dose of a beta blocker (bisoprolol 2.5-5 mg once daily) perioperatively also benefits patients with cardiovascular risk factors who undergo vascular surgery. Large doses, however, cause cerebrovascular events that are probably caused by hypotension.

Heart failure

  • Decompensated heart failure will significantly increase the operative risk, and only urgent surgery should be undertaken.
  • Compensated heart failure also increases the risk moderately.

Valvular heart disease

  • Symptomatic aortic stenosis that decreases exercise tolerance represents a high risk as regards non-cardiac surgery. The patient should be referred for cardiac surgery.
  • Asymptomatic valvular disease does not prevent surgery. Prophylaxis against endocarditis is often indicated.Prevention of Bacterial Endocarditis
  • Mitral valve prosthesis is subject to thrombosis, which leads to malfunction of the valve. Anticoagulation must not be stopped even temporarily unless the indications are vital Heart Valve Operation: Patient Follow-Up and Complications. Low molecular weight heparin (LMWH) must be started as antithrombotic medication when warfarin is discontinued.

Arrhythmias

  • In most cases arrhythmia only requires intensified monitoring but is not a contraindication to surgery. Acute atrial fibrillation should be treated before surgery.

Anticoagulation therapy

  • The referring physician should inform the surgeon and the patient regarding the importance of anticoagulation.
  • Anticoagulation therapy of patients with valve prosthesis must usually not be discontinued unless absolutely required by the operation. If there is a need to discontinue warfarin therapy, bridging therapy and an LMWH must be started Heart Valve Operation: Patient Follow-Up and Complications.
  • Anticoagulation may often be reduced (INR 1.5) for a few days (when a moderately long time has lapsed since pulmonary embolism; chronic atrial fibrillation, TIA). In this case, LMWH can be initiated on the evening of the operation day and continued until INR has been at therapeutic level for a couple of days.
  • INR value is monitored perioperatively on a daily basis, also in the morning of the operation day.

Hypertension

  • Controlled hypertension without complications does not significantly increase operative risk. Medication should continue right up to surgery. Complicated hypertension is often associated with impaired renal function and disturbances of the cerebral circulation.

Diabetes mellitus

  • Diabetes is associated with increased risk of cardiovascular disease and, in some cases, multi-organ damage.
  • When assessing the operability of the patient, attention should be paid to blood glucose control and to comorbidities.
  • As a rule of thumb, the patient's standard treatment should be interfered with as little as possible.
  • Metformin should be stopped and the patient should temporarily switch over to insulin a few days before surgery.
  • The prevention of perioperative hyperglycaemia (blood glucose > 10 mmol/l) is very important in order to prevent complications and infections from occurring. If the patient uses long-acting insulin, it is usually administered also on the operation day. If necessary, hypoglycaemia is prevented by glucose infusion.
  • Recovery may be complicated by reduced renal function, proneness to infections and delayed wound healing.
  • The routine investigations include:
    • blood glucose both on the day before surgery and on the morning of surgery, HbA1c and plasma creatinine or GFR
    • ECG.

Obesity

  • Pathological changes in almost all vital organs follow if normal body weight is significantly exceeded (BMI > 30).
  • Morbidly obese patients (BMI > 40) are at an increased operative risk. They are not suitable for day case surgery.
  • Anaesthetic risks arise from breathing and circulation problems.
  • The pulmonary function of obese patients is impaired due to the pressure exerted by the abdomen on the lungs in recumbent position.
  • The risk of thromboembolic complications is also increased.
  • If surgery is planned for an obese patient, particularly abdominal or thoracic surgery, the following investigations are always necessary:
    • chest x-ray
    • ECG
    • spirometry and often blood gas analysis.

Respiratory diseases

  • Acute mild viral upper respiratory tract infection does not warrant postponement of the operation provided that the operation is not directed at the respiratory organs and that the patient is not intubated.
  • In other cases, the operation should be postponed for 1-2 weeks in uncomplicated upper respiratory tract infections and for 4-6 weeks in lower respiratory tract infections (bronchitis, pneumonia).
  • Tolerance to exertion is crucial for operability. Dyspnoea at rest and while speaking reflects a reduced respiratory reserve. Chronic pulmonary disease must be treated optimally. Pulmonary obstruction of COPD and asthma patients must not be worse than normal, nor should these patients have bacterial infections which require treatment. COPD is often associated with coronary heart disease.
  • Smoking cessation should take place as soon as possible before the operation, but even a short non-smoking period is better than continuation of smoking.
  • If FEV1 is less than 50% of normal, upper abdominal surgery impairs the pulmonary function more than gynaecological or orthopaedic surgery.
  • Spirometry is used to assess the risks of respiratory problems and is indicated for
    • patients with asthma or COPD as well as heavy smokers if upper abdominal surgery is planned.
    • As well as carrying out spirometry, other diseases which may affect the patient's eligibility for surgery should be taken into account.
    • If spirometry reveals obstruction and a response to a bronchodilator, an inhaled bronchodilating drug and glucocorticoid should be started.

Neurological diseases

  • Recent stroke and TIA will usually result in elective surgery being postponed by 3 months. Carotid artery ultrasonography should be performed before the operation.
  • A surgical intervention directed at the carotid artery may be performed without a delay time after TIA or a minor cerebral infarction. Antithrombotic therapy is not interrupted.

Excessive alcohol consumption

  • Most changes due to excessive alcohol consumption will be fully or partially normalized within 1-2 months of alcohol abstinence.
  • Liver failure caused by alcohol affects blood coagulation.
  • A prolonged period of alcohol consumption causes non-diabetic ketoacidosis and disturbances in fluid and electrolyte balance and in nutrition, especially deficiency of vitamin B1.
  • Some patients with liver cirrhosis may be asymptomatic but even the slightest stress may cause an imbalance in the liver homeostasis.
  • If a liver disease is suspected, blood platelet count and INR should be checked.

Smoking Preoperative Smoking Cessation and Postoperative Complications

  • Smoking cessation 3-6 weeks before the operation at the latest reduces postoperative complications. There is no evidence on the benefits of a shorter period of non-smoking, but preoperative counselling and guidance concerning smoking cessation is recommended.

Preoperative assessment of cataract surgery patients

  • Cataract is usually operated on under local anaesthesia.
  • General anaesthesia is required for restless, non-cooperative patients and those with marked tremor.
  • After operation the patient is allowed to mobilise immediately.
  • Patients with cataracts often have many concomitant diseases. Acute or chronic cough for any reason can be problematic for cataract surgery. Patients with orthopnoea are unsuitable for cataract surgery.

Patient selection for day case surgery

  • Most decisions regarding the patient's fitness for day case surgery are made by the surgeon in association with the general decision of operating on the patient. Not all patients are necessarily called to a preoperative visit but the decision concerning the operation can be made on the basis of the referral. In this case the surgeon should ensure that the medical records contain all the necessary information for him/her to make a decision regarding the need for a preoperative interview and whether the patient is eligible for day case surgery.
  • Referral should provide information on
    • diseases which may increase the operative risk
    • drugs and their indications (e.g. warfarin)
    • laboratory and radiographic investigations performed
    • home circumstances
    • responsible adult to take the patient home and stay with the patient over the postoperative night
    • capacity of the patient's own primary care team to provide support
    • an anaesthetic questionnaire to the patient, depending on local practice.
  • Day case surgery is not suited in
    • open abdominal surgery
    • unstable ASA III or ASA IV patient
    • morbidly obese patient (BMI > 40)
      • Mild or moderate obesity is not an impediment to day surgery, but associated diseases have to taken into account.
    • alcoholism and drug abuse
    • severe sleep apnoea
    • social problems; a patient who does not understand instructions or has no support person at home.

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